=============================== [ INFO: suspicious RCU usage. ] 4.4.171+ #12 Not tainted ------------------------------- net/ipv6/ip6_fib.c:1465 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 7 locks held by syz-executor2/2132: #0: (sb_writers#6){.+.+.+}, at: [] sb_start_write include/linux/fs.h:1517 [inline] #0: (sb_writers#6){.+.+.+}, at: [] mnt_want_write+0x3f/0xb0 fs/namespace.c:391 #1: (&type->i_mutex_dir_key#4/1){+.+.+.}, at: [] filename_create+0x159/0x460 fs/namei.c:3511 #2: (policy_rwlock){.+.+..}, at: [] security_sid_to_context_core security/selinux/ss/services.c:1276 [inline] #2: (policy_rwlock){.+.+..}, at: [] security_sid_to_context_core+0x14e/0x200 security/selinux/ss/services.c:1245 #3: (((&net->ipv6.ip6_fib_timer))){+.-...}, at: [] lockdep_copy_map include/linux/lockdep.h:165 [inline] #3: (((&net->ipv6.ip6_fib_timer))){+.-...}, at: [] call_timer_fn+0xde/0x850 kernel/time/timer.c:1175 #4: (fib6_gc_lock){+.-...}, at: [] spin_lock_bh include/linux/spinlock.h:307 [inline] #4: (fib6_gc_lock){+.-...}, at: [] fib6_run_gc+0x3a/0x230 net/ipv6/ip6_fib.c:1811 #5: (rcu_read_lock){......}, at: [] __fib6_clean_all+0x0/0x240 net/ipv6/ip6_fib.c:1698 #6: (&tb->tb6_lock){++--..}, at: [] __fib6_clean_all+0xe8/0x240 net/ipv6/ip6_fib.c:1712 stack backtrace: CPU: 1 PID: 2132 Comm: syz-executor2 Not tainted 4.4.171+ #12 0000000000000000 373cb6aa75d0773f ffff8801db707940 ffffffff81aacd31 ffff8801927ac700 0000000000000000 0000000000000001 00000000000005b9 ffff8801d4e95f00 ffff8801db707970 ffffffff813ab5d0 ffff8801db707b90 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [] lockdep_rcu_suspicious.cold+0x10a/0x149 kernel/locking/lockdep.c:4305 [] fib6_del+0x7ea/0xae0 net/ipv6/ip6_fib.c:1465 [] fib6_clean_node+0x29c/0x500 net/ipv6/ip6_fib.c:1652 [] fib6_walk_continue+0x3e0/0x630 net/ipv6/ip6_fib.c:1578 [] fib6_walk+0x91/0xe0 net/ipv6/ip6_fib.c:1623 [] fib6_clean_tree+0xe8/0x120 net/ipv6/ip6_fib.c:1697 [] __fib6_clean_all+0x100/0x240 net/ipv6/ip6_fib.c:1713 [] fib6_clean_all net/ipv6/ip6_fib.c:1724 [inline] [] fib6_run_gc+0xaf/0x230 net/ipv6/ip6_fib.c:1821 [] fib6_gc_timer_cb+0x1d/0x30 net/ipv6/ip6_fib.c:1836 [] call_timer_fn+0x18d/0x850 kernel/time/timer.c:1185 [] __run_timers kernel/time/timer.c:1261 [inline] [] run_timer_softirq+0x51f/0xb70 kernel/time/timer.c:1444 [] __do_softirq+0x226/0xa3f kernel/softirq.c:273 [] invoke_softirq kernel/softirq.c:350 [inline] [] irq_exit+0x10a/0x150 kernel/softirq.c:391 [] exiting_irq arch/x86/include/asm/apic.h:652 [inline] [] smp_apic_timer_interrupt+0x7e/0xb0 arch/x86/kernel/apic/apic.c:926 [] apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:768 [] ? kmalloc include/linux/slab.h:481 [inline] [] ? context_struct_to_string security/selinux/ss/services.c:1216 [inline] [] ? context_struct_to_string+0x371/0x690 security/selinux/ss/services.c:1188 [] dump_trace+0x179/0x390 arch/x86/kernel/dumpstack_64.c:243 [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack mm/kasan/kasan.c:512 [inline] [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_kmalloc.part.0+0x62/0xf0 mm/kasan/kasan.c:616 [] kasan_kmalloc+0xb7/0xd0 mm/kasan/kasan.c:601 [] __kmalloc+0x141/0x330 mm/slub.c:3613 [] kmalloc include/linux/slab.h:481 [inline] [] context_struct_to_string security/selinux/ss/services.c:1216 [inline] [] context_struct_to_string+0x371/0x690 security/selinux/ss/services.c:1188 [] security_sid_to_context_core security/selinux/ss/services.c:1287 [inline] [] security_sid_to_context_core+0x18a/0x200 security/selinux/ss/services.c:1245 [] security_sid_to_context_force+0x2b/0x40 security/selinux/ss/services.c:1312 [] selinux_inode_init_security+0x440/0x680 security/selinux/hooks.c:2777 [] security_inode_init_security security/security.c:382 [inline] [] security_inode_init_security+0x1a2/0x370 security/security.c:366 [] shmem_mknod+0xbf/0x240 mm/shmem.c:2232 [] shmem_mkdir+0x29/0x50 mm/shmem.c:2278 [] vfs_mkdir2+0x293/0x480 fs/namei.c:3690 [] SYSC_mkdirat fs/namei.c:3719 [inline] [] SyS_mkdirat+0x144/0x250 fs/namei.c:3703 [] SYSC_mkdir fs/namei.c:3730 [inline] [] SyS_mkdir+0x22/0x30 fs/namei.c:3728 [] entry_SYSCALL_64_fastpath+0x1e/0x9a audit_printk_skb: 18 callbacks suppressed audit: type=1400 audit(1548599515.895:2219): avc: denied { create } for pid=10181 comm="syz-executor2" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0 audit: type=1400 audit(1548599516.175:2220): avc: denied { create } for pid=10239 comm="syz-executor4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0 audit: type=1400 audit(1548599516.235:2221): avc: denied { create } for pid=10239 comm="syz-executor4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0 audit: type=1400 audit(1548599516.445:2222): avc: denied { create } for pid=10257 comm="syz-executor3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=0 audit: type=1400 audit(1548599516.445:2223): avc: denied { create } for pid=10251 comm="syz-executor4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0 audit: type=1400 audit(1548599516.545:2224): avc: denied { create } for pid=10267 comm="syz-executor4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0 audit: type=1400 audit(1548599516.705:2225): avc: denied { create } for pid=10278 comm="syz-executor4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0 audit: type=1400 audit(1548599516.715:2226): avc: denied { create } for pid=10259 comm="syz-executor2" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0 audit: type=1400 audit(1548599516.895:2227): avc: denied { create } for pid=10291 comm="syz-executor4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0 audit: type=1400 audit(1548599517.045:2228): avc: denied { create } for pid=10257 comm="syz-executor3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=0 audit_printk_skb: 96 callbacks suppressed audit: type=1400 audit(1548599521.675:2261): avc: denied { create } for pid=10574 comm="syz-executor2" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0 audit: type=1400 audit(1548599521.975:2262): avc: denied { create } for pid=10583 comm="syz-executor3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0 audit: type=1400 audit(1548599522.095:2263): avc: denied { create } for pid=10574 comm="syz-executor2" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0 audit: type=1400 audit(1548599522.595:2264): avc: denied { create } for pid=10624 comm="syz-executor2" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0 audit: type=1400 audit(1548599523.035:2265): avc: denied { create } for pid=10624 comm="syz-executor2" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0